Buggy code:
public class KoyaContentService { private final Logger logger = Logger . getLogger ( this . getClass ( ) ) ; private NodeService nodeService ; private KoyaNodeService koyaNodeService ; protected DictionaryService dictionaryService ; protected ContentService contentService ; protected NamespaceService namespaceService ; protected FileFolderService fileFolderService ; protected ActionService actionService ; public void setNodeService ( NodeService nodeService ) { } public void setKoyaNodeService ( KoyaNodeService koyaNodeService ) { } public void setDictionaryService ( DictionaryService dictionaryService ) { } public void setContentService ( ContentService contentService ) { } public void setNamespaceService ( NamespaceService namespaceService ) { } public void setFileFolderService ( FileFolderService fileFolderService ) { } public void setActionService ( ActionService actionService ) { } public Directory createDir ( String title , NodeRef parent ) throws KoyaServiceException { } public Directory makeFolders ( NodeRef parentNodeRef , List < String > pathElements ) throws KoyaServiceException { if ( ! ( ( nodeService . getType ( parentNodeRef ) . equals ( TYPE_DOSSIER ) ) || ( nodeService . getType ( parentNodeRef ) . equals ( TYPE_FOLDER ) ) ) ) { throw new KoyaServiceException ( KoyaErrorCodes . DIR_CREATION_INVALID_PARENT_TYPE ) ; } if ( ( pathElements != null ) && ( ( pathElements . size ( ) ) == 0 ) ) { throw new IllegalArgumentException ( "Path<seq2seq4repair_space>element<seq2seq4repair_space>list<seq2seq4repair_space>is<seq2seq4repair_space>empty" ) ; } NodeRef currentParentRef = parentNodeRef ; for ( final String pathElement : pathElements ) { if ( ( pathElement != null ) && ( ! ( pathElement . isEmpty ( ) ) ) ) { <START_BUG> NodeRef nodeRef = AuthenticationUtil . runAsSystem ( new KoyaContentService . SearchAsSystem ( fileFolderService , parentNodeRef , koyaNodeService . getUniqueValidFileNameFromTitle ( pathElement ) ) ) ; <END_BUG> if ( nodeRef == null ) { try { Directory directory = createDir ( pathElement , currentParentRef ) ; currentParentRef = currentParentRef = directory . getNodeRefasObject ( ) ; } finally { } } else { currentParentRef = nodeRef ; } } } return koyaNodeService . getSecuredItem ( currentParentRef , Directory . class ) ; } private static class SearchAsSystem implements AuthenticationUtil . RunAsWork < NodeRef > { FileFolderService service ; NodeRef node ; String name ; SearchAsSystem ( FileFolderService service , NodeRef node , String name ) { } public NodeRef doWork ( ) throws Exception { } } public List < Content > list ( NodeRef parent , Integer depth , Boolean folderOnly ) { } public Map < String , String > createContentNode ( NodeRef parent , String fileName , org . springframework . extensions . surf . util . Content content ) throws KoyaServiceException { } public Map < String , String > createContentNode ( NodeRef parent , String fileName , InputStream contentInputStream ) throws KoyaServiceException { } public Map < String , String > createContentNode ( NodeRef parent , String fileName , String name , InputStream contentInputStream ) throws KoyaServiceException { } public Map < String , String > createContentNode ( NodeRef parent , String fileName , String name , String mimetype , String encoding , InputStream contentInputStream ) throws KoyaServiceException { } public File zip ( List < String > nodeRefs ) throws KoyaServiceException { } public static final List < String > ZIP_MIMETYPES = Collections . unmodifiableList ( new ArrayList ( ) { } ) ; private void addToZip ( NodeRef node , ZipArchiveOutputStream out , String path ) throws IOException { } }

Fix:
NodeRef nodeRef = AuthenticationUtil . runAsSystem ( new KoyaContentService . SearchAsSystem ( fileFolderService , currentParentRef , koyaNodeService . getUniqueValidFileNameFromTitle ( pathElement ) ) ) ;